<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .container {
            width: 1200px;
            height: 900px;
            background-color: pink;
            border: 1px solid #000;
            margin: 0 auto;
            display: flex;
            /* 多条轴表示多行 */
            flex-wrap: wrap;
            
            /* 多条轴更改交叉轴对齐方式 */
            /* align-content: flex-end; */
            /* align-content: flex-start; */
            /* align-content: center; */
            /* align-content: space-around; */
            align-content: space-between;
            /* align-content: space-evenly; */

        }
        .box {
            width: 150px;
            height: 150px;
            border: 5px solid green;
            background-color: skyblue;
            font-size: 40px;
            color: #fff;
            text-align: center;
        }
        .box1 {
            width: 200px;
            height: 100px;
        }
        .box2 {
            width: 300px;
            height: 250px;
        }
        .box3 {
            width: 100px;
            height: 300px;
        } 
        .box4 {
            width: 250px;
            height: 200px;
        } 
    </style>
</head>
<body>
    <div class="container">
        <div class="box box1">1</div>
        <div class="box box2">2</div>
        <div class="box box3">3</div>
        <div class="box box4">4</div>
        <div class="box box1">1</div>
        <div class="box box2">2</div>
        <div class="box box3">3</div>
        <div class="box box4">4</div>
    </div>
</body>
</html>